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Comment by cousinbryce | Hacker News Reader

Anyone have guesses about how a transiting primordial black hole would effect a Sun like star? Paper is about tidal forces inducing supernova in white dwarfs. For that matter how might it effect sea tides?

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Most likely minimal? The mass is low.

I am, however, reminded that the orbit of the asteroid Juno (~250km diameter) permanently changed in 1839 without an obvious cause.

How to spot tiny black holes that might pass through the solar system - https://www.sciencenews.org/article/primordial-black-holes-s...

And the referenced papers:

Probing primordial black holes and dark matter clumps in the Solar System with gravimeter and Global Navigation Satellite Systems networks - https://journals.aps.org/prd/abstract/10.1103/PhysRevD.110.0...

Close encounters of the primordial kind: A new observable for primordial black holes as dark matter - https://journals.aps.org/prd/abstract/10.1103/PhysRevD.110.0...

And the PBS Spacetime: How Many Black Holes Are In The Solar System? - https://youtu.be/wh75ubECL8I

Wouldn't low-mass primordial black holes have evaporated by now?

Depends on what "low mass" means. An earth-mass black hole lasts 10^50 years. A black hole the mass of Mount Everest lasts 10^21 years.

Black holes on the order of metric tons would have evaporated by now. But primordial black holes can come in any size, and there is a vast range of them that will exist much longer than the universe has already existed.

Note that the orbital perturbation of Juno in 1839 was of rather low magnitude, and could have been caused by an asteroid as small as ~1km diameter. Based on current models, there are potentially more than a million rocks that big in the belt still undiscovered.

For the latter, you mught enjoy Greg Egan's "Perihelion Summer".

We have constraints that primordial black holes must be less than the size of a large asteroid. They would be gravitationally insignificant to the Earth unless they actually passed through it.

I also don't think it would really be detectable in the Sun. Perhaps there would be some transient astroseismology signature.

Picturing the crust of the earth being pulled off like an orange peel. But maybe seen too much scifi so it's probably a lot more boring :/

I think at the energy scales we're talking about, everything involved would basically act like a fluid.

This is correct, the Earth is effectively a ball of water, and would get blended/smeared/sheared like if you toss water across a yard out of a cup.

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